The invention relates to a device and a method for indicating the engine speed in a motor vehicle, having a sensor, which detects the actual engine speed, at least one electronic module, which processes the detected engine speed signal, and an engine speed display module, which is operatively coupled with the electronic module in order to display an engine speed.
Such a device is known, for example, from German patent document DE 10 2004 033 003 A1. According to this known device, there exists an engine speed indicator, which does, in fact, try to adapt this display to certain operating conditions in the motor vehicle, such as during a gear change. However, this prior art display always proceeds from the detected or measured speed and processes it correspondingly. Owing to such a manipulation of the measured speed, radical deviations from the actual speed can be displayed, a feature that can irritate the driver.
The invention provides a device of the aforementioned type, which provides a true correlation between the planned speed characteristics during a gear change and the displayed speed. A method for indicating the engine speed in a motor vehicle is also provided.
The device according to the invention for indicating the engine speed exhibits a sensor, which detects the actual engine speed; an electronic module, which processes the detected engine speed signal; and an engine speed display module. The engine speed display module can be integrated, for example, into a so-called instrument cluster. The electronic module can be integrated, for example, into an internal combustion engine control unit or a transmission control unit or also into the instrument cluster. In order to indicate the engine speed, the engine speed display module acquires from the electronic module in a manner that is well known the engine speed that is to be displayed. In addition, the detected engine speed signal may be displayed, modified or unmodified, via a connection of the electronic module with the display module.
However, in a radical departure from the prior art devices for indicating the engine speed, an engine speed signal, which is independent of the detected engine speed signal, is output, according to the invention, by way of an electronic transmission control module in the vehicle during a gear speed change. The gear change start is defined, preferably upon passage of a delay time following an electronic command to initiate a gear change. In this case, the delay time corresponds, in particular, to the dead time of the hydraulics and the remaining actuators prior to the actual gear change, which leads then to an engine speed change. However, in a preferred embodiment, the start of a predetermined nominal engine speed characteristic for a gear change control may also be defined as the gear change start.
There already exist at least internally electronic transmission control modules, for example, in the form of stand-alone control units for automatic transmissions or for automated transmissions, which specify a nominal engine speed characteristic during a gear change.
By way of the invention, a correlation between the subjective gear change impression and the displayed speed characteristic can be produced.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.